Announcement

Collapse
No announcement yet.

? Trying DHCP with 2 networks in SBS 2003

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • ? Trying DHCP with 2 networks in SBS 2003

    This is the problem I currently have.

    - We have 2 "networks" split between two offices. Both are connected with a T1, and both have 2 DSL lines (1 for web surfing, 1 for Exchange/e-mail).

    - At both locations, the Domain Controller (SBS 2003) is used as the PDC, Exchange & DNS server.

    - At location #1 that DC (SBS 2003) is also the DHCP server, issuing leases out. Location #1 all clients (25) are dynamically assigned, while location #2 is static because it picks up the DHCP server from location #1 whenever set to dynamic.

    - Basically want to figure out a way to have them inter-operate with file sharing and network access but possible run DHCP on both DC's (I know though it's not possible). So a solution would be... help? Both networks use the 192.168.1.x IP ranges and 255.255.255.0 subnet, with their prospective gateways.

    - Straight down to it, want to be able to have DHCP running at both locations, so when users "plug-in" from that location, THAT specific DC will assign a DHCP address rather than the other location's DHCP server picking it up.

  • #2
    Re: ? Trying DHCP with 2 networks in SBS 2003

    First, I think that you need to setup DHCP replay agent in the switchs/routers so they will forward DHCP request only if the local DHCP is off to other site.
    Then, you will need to create sepreate scope like:

    192.168.0.21/24-192.168.168.0.100/24
    for site A

    Primay DNS\WINS 192.168.0.10 (Server Site A)

    Second DNS\WINS 192.168.0.110 (Server site B)

    192.168.0.121/24-192.168.168.0.254/24
    for site B

    Primay DNS\WINS 192.168.0.110 (Server Site A)

    Second DNS\WINS 192.168.0.10 (Server site B)


    The default gateway should be the same in this exmple for both scopes.

    You may need to disble Rogue DHCP Server Detection in some cases:

    http://msmvps.com/blogs/obts/archive.../05/65482.aspx

    Regards,

    Yuval
    Best Regards,

    Yuval Sinay

    LinkedIn: https://www.linkedin.com/in/yuval14, Blog: http://blogs.microsoft.co.il/blogs/yuval14

    Comment


    • #3
      Re: ? Trying DHCP with 2 networks in SBS 2003

      > THAT specific DC will assign a DHCP address rather than the other location's DHCP server picking it up.
      ...
      > Both networks use the 192.168.1.x IP ranges and 255.255.255.0 subnet

      This is interesting. It implies that you have set up a bridge between the two locations, making the network transparent on the data layer. Is that correct?

      If you do it this way you cannot meaningfully separate the two networks. DHCP cannot see the difference between the networks.

      What people usually do to separate the networks is to create two subnets, and enable routing between them. SBS can do that, if you want to. Once you have that, each SBS can have its own DHCP.

      Comment


      • #4
        Re: ? Trying DHCP with 2 networks in SBS 2003

        Yes they are 2 separate networks (physically) in two different states,
        connected by 1 T1 connection.

        However they both have the same Subnet Mask and IP headers and share the same IP range (Ex. 100-150 is Location 1, 151-200 is Location 2). DHCP server is only running in Location 2 and Location 1 all clients are static.

        When a "new" user has his computer set for DHCP (no matter where his location is) it points to the DHCP server in Location 2.

        I would like to be able for us to run a DHCP server in both locations and for the network to be smart enough to figure out where the user is "plugging" in either location 1 or 2.

        Comment


        • #5
          Re: ? Trying DHCP with 2 networks in SBS 2003

          Why are you running the two SBS networks as one anyway? What are they sharing? How are they connected (other than by T1) Does each SBS have 2 or 1 NIC?
          I think without further information we cannot really answer what you are trying to accomplish other than in general terms. So the others are correct - either create two separate subnets and route. Disable DHCP relay at both sites. Also make one server give out addresses 192.168.16.10-127 and the other one give out addresses 192.168.16.128-246 but watch which IPs you use for your servers. You could also disable the DHCP relay agent.
          If you use 2 nics in your SBS you can effectively isolate each LAN from the other. Also use a 255.255.255.128 subnet mask if you want to use VPN or otherwise route between the networks.
          Again describe better what you are trying to accomplish and you will get better answers.
          TIA

          Steven Teiger [SBS-MVP(2003-2009)]
          http://www.wintra.co.il/
          sigpic
          Iím honoured to have been selected for the SMB 150 list for 2013. This is the third time in succession (no logo available for 2011) that I have been honoured with this award.

          We donít stop playing because we grow old, we grow old because we stop playing.

          Comment


          • #6
            Re: ? Trying DHCP with 2 networks in SBS 2003

            Basically we are avoiding putting two subnets..

            I'm asking because we have 2 locations both tied in through a T1 connection. Location 1 has a DHCP server, so location 2 has all Static IP's because they are on the same subnet. Instead of making another subnet, we were just thinking about blocking the port DHCP services uses in 2003 SBS on the T1 router.

            Comment

            Working...
            X